github.com/megatontech/mynoteforgo@v0.0.0-20200507084910-5d0c6ea6e890/源码/net/udpsock_plan9_test.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package net
     6  
     7  import (
     8  	"internal/testenv"
     9  	"runtime"
    10  	"testing"
    11  )
    12  
    13  func TestListenMulticastUDP(t *testing.T) {
    14  	testenv.MustHaveExternalNetwork(t)
    15  
    16  	ifcs, err := Interfaces()
    17  	if err != nil {
    18  		t.Skip(err.Error())
    19  	}
    20  	if len(ifcs) == 0 {
    21  		t.Skip("no network interfaces found")
    22  	}
    23  
    24  	var mifc *Interface
    25  	for _, ifc := range ifcs {
    26  		if ifc.Flags&FlagUp|FlagMulticast != FlagUp|FlagMulticast {
    27  			continue
    28  		}
    29  		mifc = &ifc
    30  		break
    31  	}
    32  
    33  	if mifc == nil {
    34  		t.Skipf("no multicast interfaces found")
    35  	}
    36  
    37  	c1, err := ListenMulticastUDP("udp4", mifc, &UDPAddr{IP: ParseIP("224.0.0.254")})
    38  	if err != nil {
    39  		t.Fatalf("multicast not working on %s", runtime.GOOS)
    40  	}
    41  	c1addr := c1.LocalAddr().(*UDPAddr)
    42  	if err != nil {
    43  		t.Fatal(err)
    44  	}
    45  	defer c1.Close()
    46  
    47  	c2, err := ListenUDP("udp4", &UDPAddr{IP: IPv4zero, Port: 0})
    48  	c2addr := c2.LocalAddr().(*UDPAddr)
    49  	if err != nil {
    50  		t.Fatal(err)
    51  	}
    52  	defer c2.Close()
    53  
    54  	n, err := c2.WriteToUDP([]byte("data"), c1addr)
    55  	if err != nil {
    56  		t.Fatal(err)
    57  	}
    58  	if n != 4 {
    59  		t.Fatalf("got %d; want 4", n)
    60  	}
    61  
    62  	n, err = c1.WriteToUDP([]byte("data"), c2addr)
    63  	if err != nil {
    64  		t.Fatal(err)
    65  	}
    66  	if n != 4 {
    67  		t.Fatalf("got %d; want 4", n)
    68  	}
    69  }